I want to create a box were the user is informed of what the application is actually doing.
I created a Text Widget were to show the print statements that I wrote in key points of the applications, so that it could serve as a log box.
To do this, I redirected the stdout to a subclass of the widget itself "upgraded" with a write method as I saw here in another post.
This does indeed work, but I noticed a problem that makes the box almost useless.
If you run the code, you can see that the sentences appear all at once. More puzzling for me is that not only the sentences of the "wait2" functions
appear togheter, but even the print statement of the calling function, "wait1", is shown at the end of the process.
Why this behaviour? what can I do to see the statement shown in the box as they are executed?
from Tkinter import *
import sys
import time
root = Tk()
class addwritemethod(object):
def __init__(self, widget):
self.widget = widget
def write(self, string):
self.widget.configure(state="normal")
self.widget.insert("end", string)
self.widget.see("end")
self.widget.configure(state="disabled")
def wait1():
print "Can you see me?"
wait2()
def wait2():
for i in range(10):
time.sleep(5)
print "Long time no see!"
t_go = Button(root, text= "Start!", width =12, command = wait1)
t_go.pack(side = LEFT, padx = 20, pady = 20)
tlog = Text(root,wrap = "word")
tlog.pack(side="top", fill="both", expand=True)
tlog.configure(state="disabled")
sys.stdout = addwritemethod(tlog)
mainloop()
EDIT: I want to say thanks to the people who answered me and an apology: I did not give all the required information.
I put time.sleep() in the test code only to show you the behaviour. In the real application, I trasfer a file via ssh with Paramiko and I don't use sleep().
Maybe I choose the wrong example, but the result is the same, all the print stament are shown at the same moment.
You could also use the built-in logging module to achieve your goal of
creating a box where the user is informed of what the application is actually doing ... a log box.
I had this same need and converged on the recommendations provided here and here.
I have an example below that I created to illustrate the concept of logging to a GUI control using Tkinter. The example below logs to a text control as you ask, but you can send log messages to other GUI components by replacing/copying the class MyHandlerText with other handler classes like MyHandlerLabel, MyHandlerListbox, etc. (choose your own names for the handler classes). Then you'd have a handler for a variety of GUI controls of interest. The big "a-ha" moment for me was the module-level getLogger concept encouraged by python.org.
import Tkinter
import logging
import datetime
# this item "module_logger" is visible only in this module,
# (but you can create references to the same logger object from other modules
# by calling getLogger with an argument equal to the name of this module)
# this way, you can share or isolate loggers as desired across modules and across threads
# ...so it is module-level logging and it takes the name of this module (by using __name__)
# recommended per https://docs.python.org/2/library/logging.html
module_logger = logging.getLogger(__name__)
class simpleapp_tk(Tkinter.Tk):
def __init__(self,parent):
Tkinter.Tk.__init__(self,parent)
self.parent = parent
self.grid()
self.mybutton = Tkinter.Button(self, text="ClickMe")
self.mybutton.grid(column=0,row=0,sticky='EW')
self.mybutton.bind("<ButtonRelease-1>", self.button_callback)
self.mytext = Tkinter.Text(self, state="disabled")
self.mytext.grid(column=0, row=1)
def button_callback(self, event):
now = datetime.datetime.now()
module_logger.info(now)
class MyHandlerText(logging.StreamHandler):
def __init__(self, textctrl):
logging.StreamHandler.__init__(self) # initialize parent
self.textctrl = textctrl
def emit(self, record):
msg = self.format(record)
self.textctrl.config(state="normal")
self.textctrl.insert("end", msg + "\n")
self.flush()
self.textctrl.config(state="disabled")
if __name__ == "__main__":
# create Tk object instance
app = simpleapp_tk(None)
app.title('my application')
# setup logging handlers using the Tk instance created above
# the pattern below can be used in other threads...
# ...to allow other thread to send msgs to the gui
# in this example, we set up two handlers just for demonstration (you could add a fileHandler, etc)
stderrHandler = logging.StreamHandler() # no arguments => stderr
module_logger.addHandler(stderrHandler)
guiHandler = MyHandlerText(app.mytext)
module_logger.addHandler(guiHandler)
module_logger.setLevel(logging.INFO)
module_logger.info("from main")
# start Tk
app.mainloop()
When you call sleep, the application does exactly that: it sleeps. When it's sleeping it can't update the display. As a general rule you should never call sleep in a GUI.
That being said, a quick fix is to make sure you call update after printing something to the log, so that Tkinter has a chance to update the screen. Add self.widget.update_idletasks() at the end of write (redrawing the screen is considered an "idle task").
This isn't a proper fix but it's good enough to illustrate why the data isn't appearing. A proper fix involves not calling sleep. There are many examples on stackoverflow related to this, and almost all of them involve using the after method.
Related
My little program has a potentially long running process. That's not a problem when doing it from the console, but now I want to add a GUI. Ideally I want to use Tkinter (a) because it's simple, and (b) because it might be easier to implement across platforms. From what I've read and experienced, (almost) all GUIs suffer the same issue anyway.
Through all my reading on the subject of threading and GUI there seem to be two streams. 1 - where the underlying worker process is polling (eg waiting to fetch data), and 2 - where the worker process is doing a lot of work (eg copying files in a for loop). My program falls into the latter.
My code has a "hierarchy" of classes.
The MIGUI class handles the GUI and interacts with the interface class MediaImporter.
The MediaImporter class is the interface between the user interface (console or GUI) and the worker classes.
The Import class is the long-running worker. It does not know that the interface or GUI classes exist.
The problem: After clicking the Start button, the GUI is blocked, so I can't click the Abort button. It is as if I'm not using threading at all. I suspect the issue is with the way I am starting the threading in startCallback method.
I've also tried the approach of threading the entire MediaImporter class. See the commented-out lines.
import tkinter as tk
from tkinter import ttk
from tkinter import filedialog
import threading
import time
class MIGUI():
def __init__(self, master):
self.master = master
self.mediaImporter = MediaImporter()
self.startButton = ttk.Button(self.master, text='Start', command=self.startCallback)
self.startButton.pack()
self.abortButton = ttk.Button(self.master, text='Abort', command=self.abortCallback)
self.abortButton.state(['disabled'])
self.abortButton.pack()
def startCallback(self):
print('startCallback')
self.abortButton.state(['!disabled'])
self.startButton.state(['disabled'])
self.abortButton.update() # forcing the update seems unnecessary
self.startButton.update()
#print(self.startButton.state())
#print(self.abortButton.state())
self.x = threading.Thread(target=self.mediaImporter.startImport)
self.x.start()
self.x.join()
#self.mediaImporter.startImport()
self.startButton.state(['!disabled'])
self.abortButton.state(['disabled'])
self.abortButton.update()
self.startButton.update()
#print(self.startButton.state())
#print(self.abortButton.state())
def abortCallback(self):
print('abortCallback')
self.mediaImporter.abortImport()
self.startButton.state(['!disabled'])
self.abortButton.state(['disabled'])
class MediaImporter():
#class MediaImporter(threading.Thread):
""" Interface between user (GUI / console) and worker classes """
def __init__(self):
#threading.Thread.__init__(self)
self.Import = Import()
#other worker classes exist too
def startImport(self):
print('mediaImporter - startImport')
self.Import.start()
def abortImport(self):
print('mediaImporter - abortImport')
self.Import.abort()
class Import():
""" Worker
Does not know anything about other non-worker classes or UI.
"""
def __init__(self):
self._wantAbort = False
def start(self):
print('import - start')
self._wantAbort = False
self.doImport()
def abort(self):
print('import - abort')
self._wantAbort = True
def doImport(self):
print('doImport')
for i in range(0,10):
#actual code has nested for..loops
print(i)
time.sleep(.25)
if self._wantAbort:
print('doImport - abort')
return
def main():
gui = True
console = False
if gui:
root = tk.Tk()
app = MIGUI(root)
root.mainloop()
if console:
#do simple console output without tkinter - threads not necessary
pass
if __name__ == '__main__':
main()
The reason your GUI is blocked is because you call self.x.join(), which blocks until the doImport function is complete, see the join documentation. Instead I would call join() in your abortCallback() function, since that is what will cause the thread to stop running.
Thank you again XORNAND. The join() was definitely part of the problem. The other part of the problem was that there was no means of the MIGUI class knowing when the long-running process was complete (either because it had run its course, or because it was aborted.) An additional layer of messaging is required between the low-level worker, and the UI layer. I did try to use threading.Event without success, and did consider using Queues.
My solution is to use pubsub. (https://github.com/schollii/pypubsub) The worker layer can sendMessage on various topics, and the UI and interface layers can set up Listeners to perform actions with received data.
In my case, the Import.doImport method sends a STATUS message when it is completed. The MIGUI listener can then flip-flop the Start/Abort buttons accordingly.
To make sure the implementation of pubsub was going to work as planned I also set up a tkinter Progressbar. The doImport method sends a PROGESS message with the percent complete. This is reflected in the on-screen Progressbar.
A side note - in my original issue I had to use .update() on the buttons to get them to display. Now that we're not blocking anymore, this is not necessary.
Posting the complete working solution here, showing the pubsub implementation.
import tkinter as tk
from tkinter import ttk
import threading
import time
from pubsub import pub
class MIGUI():
def __init__(self, master):
self.master = master
self.mediaImporter = MediaImporter()
self.startButton = ttk.Button(self.master, text='Start', command=self.startCallback)
self.startButton.pack()
self.abortButton = ttk.Button(self.master, text='Abort', command=self.abortCallback)
self.abortButton.state(['disabled'])
self.abortButton.pack()
self.progress = ttk.Progressbar(self.master, length=300)
self.progress.pack()
pub.subscribe(self.statusListener, 'STATUS')
pub.subscribe(self.progressListener, 'PROGRESS')
def statusListener(self, status, value):
print('MIGUI', status, value)
if status == 'copying' and (value == 'finished' or value == 'aborted'):
self.startButton.state(['!disabled'])
self.abortButton.state(['disabled'])
def progressListener(self, value):
print('Progress %d' % value)
self.progress['maximum'] = 100
self.progress['value'] = value
def startCallback(self):
print('startCallback')
self.abortButton.state(['!disabled'])
self.startButton.state(['disabled'])
self.x = threading.Thread(target=self.mediaImporter.startImport)
self.x.start()
# original issue had join() here, which was blocking.
def abortCallback(self):
print('abortCallback')
self.mediaImporter.abortImport()
class MediaImporter():
""" Interface between user (GUI / console) and worker classes """
def __init__(self):
self.Import = Import()
#other worker classes exist too
pub.subscribe(self.statusListener, 'STATUS')
def statusListener(self, status, value):
#perhaps do something
pass
def startImport(self):
self.Import.start()
def abortImport(self):
self.Import.abort()
class Import():
""" Worker
Does not know anything about other non-worker classes or UI.
It does use pubsub to publish messages - such as the status and progress.
The UI and interface classes can subsribe to these messages and perform actions. (see listener methods)
"""
def __init__(self):
self._wantAbort = False
def start(self):
self._wantAbort = False
self.doImport()
def abort(self):
pub.sendMessage('STATUS', status='abort', value='requested')
self._wantAbort = True
def doImport(self):
self.max = 13
pub.sendMessage('STATUS', status='copying', value='started')
for i in range(1,self.max):
#actual code has nested for..loops
progress = ((i+1) / self.max * 100.0)
pub.sendMessage('PROGRESS', value=progress)
time.sleep(.1)
if self._wantAbort:
pub.sendMessage('STATUS', status='copying', value='aborted')
return
pub.sendMessage('STATUS', status='copying', value='finished')
def main():
gui = True
console = False
if gui:
root = tk.Tk()
app = MIGUI(root)
root.mainloop()
if console:
#do simple console output without tkinter - threads not necessary
pass
if __name__ == '__main__':
main()
I want to add a control terminal widget to my pure python+tkinter application similar to the python interpreter provided in Blender. It should be running within the same context (process) so the user can add features and control the application that is currently running from the control widget. Ideally I'd like it to also "hijack" stdout and stderr of the current application so it will report any problems or debugging information within the running application.
This is what I have come up with so far. The only problems are that it isn't responding to commands, and the thread doesn't stop when the user closes the window.
import Tkinter as tk
import sys
import code
from threading import *
class Console(tk.Frame):
def __init__(self,parent=None):
tk.Frame.__init__(self, parent)
self.parent = parent
sys.stdout = self
sys.stderr = self
self.createWidgets()
self.consoleThread = ConsoleThread()
self.after(100,self.consoleThread.start)
def write(self,string):
self.ttyText.insert('end', string)
self.ttyText.see('end')
def createWidgets(self):
self.ttyText = tk.Text(self.parent, wrap='word')
self.ttyText.grid(row=0,column=0,sticky=tk.N+tk.S+tk.E+tk.W)
class ConsoleThread(Thread):
def __init__(self):
Thread.__init__(self)
def run(self):
vars = globals().copy()
vars.update(locals())
shell = code.InteractiveConsole(vars)
shell.interact()
if __name__ == '__main__':
root = tk.Tk()
root.config(background="red")
main_window = Console(root)
main_window.mainloop()
try:
if root.winfo_exists():
root.destroy()
except:
pass
I have the answer in case anyone still cares! (I have also changed to python 3, hence the import tkinter rather than import Tkinter)
I have changed the approach slightly from the original by using a separate file to run the InteractiveConsole, and then making the main file open this other file (which I have called console.py and is in the same directory) in a subprocess, linking the stdout, stderr, and stdin of this subprocess to the tkinter Text widget programatically.
Here is the code in the for the console file (if this is run normally, it acts like a normal console):
# console.py
import code
if __name__ == '__main__':
vars = globals().copy()
vars.update(locals())
shell = code.InteractiveConsole(vars)
shell.interact()
And here is the code for the python interpreter, that runs the console inside the Text widget:
# main.py
import tkinter as tk
import subprocess
import queue
import os
from threading import Thread
class Console(tk.Frame):
def __init__(self,parent=None):
tk.Frame.__init__(self, parent)
self.parent = parent
self.createWidgets()
# get the path to the console.py file assuming it is in the same folder
consolePath = os.path.join(os.path.dirname(__file__),"console.py")
# open the console.py file (replace the path to python with the correct one for your system)
# e.g. it might be "C:\\Python35\\python"
self.p = subprocess.Popen(["python3",consolePath],
stdout=subprocess.PIPE,
stdin=subprocess.PIPE,
stderr=subprocess.PIPE)
# make queues for keeping stdout and stderr whilst it is transferred between threads
self.outQueue = queue.Queue()
self.errQueue = queue.Queue()
# keep track of where any line that is submitted starts
self.line_start = 0
# make the enter key call the self.enter function
self.ttyText.bind("<Return>",self.enter)
# a daemon to keep track of the threads so they can stop running
self.alive = True
# start the functions that get stdout and stderr in separate threads
Thread(target=self.readFromProccessOut).start()
Thread(target=self.readFromProccessErr).start()
# start the write loop in the main thread
self.writeLoop()
def destroy(self):
"This is the function that is automatically called when the widget is destroyed."
self.alive=False
# write exit() to the console in order to stop it running
self.p.stdin.write("exit()\n".encode())
self.p.stdin.flush()
# call the destroy methods to properly destroy widgets
self.ttyText.destroy()
tk.Frame.destroy(self)
def enter(self,e):
"The <Return> key press handler"
string = self.ttyText.get(1.0, tk.END)[self.line_start:]
self.line_start+=len(string)
self.p.stdin.write(string.encode())
self.p.stdin.flush()
def readFromProccessOut(self):
"To be executed in a separate thread to make read non-blocking"
while self.alive:
data = self.p.stdout.raw.read(1024).decode()
self.outQueue.put(data)
def readFromProccessErr(self):
"To be executed in a separate thread to make read non-blocking"
while self.alive:
data = self.p.stderr.raw.read(1024).decode()
self.errQueue.put(data)
def writeLoop(self):
"Used to write data from stdout and stderr to the Text widget"
# if there is anything to write from stdout or stderr, then write it
if not self.errQueue.empty():
self.write(self.errQueue.get())
if not self.outQueue.empty():
self.write(self.outQueue.get())
# run this method again after 10ms
if self.alive:
self.after(10,self.writeLoop)
def write(self,string):
self.ttyText.insert(tk.END, string)
self.ttyText.see(tk.END)
self.line_start+=len(string)
def createWidgets(self):
self.ttyText = tk.Text(self, wrap=tk.WORD)
self.ttyText.pack(fill=tk.BOTH,expand=True)
if __name__ == '__main__':
root = tk.Tk()
root.config(background="red")
main_window = Console(root)
main_window.pack(fill=tk.BOTH,expand=True)
root.mainloop()
The reason that reading from stdout and stderr is in separate threads is because the read method is blocking, which causes the program to freeze until the console.py subprocess gives more output, unless these are in separate threads. The writeLoop method and the queues are needed to write to the Text widget since tkinter is not thread safe.
This certainly still has problems to be ironed out, such as the fact that any code on the Text widget is editable even once already submitted, but hopefully it answers your question.
EDIT: I've also neatened some of the tkinter such that the Console will behave more like a standard widget.
it isn't responding to commands
The reason it isn't responding to commands is because you haven't linked the Text widget (self.ttyText) into stdin. Currently when you type it adds text into the widget and nothing else. This linking can be done similarly to what you've already done with stdout and stderr.
When implementing this, you need to keep track of which part of the text in the widget is the text being entered by the user - this can be done using marks (as described here).
the thread doesn't stop when the user closes the window.
I don't think there is a "clean" way to solve this issue without a major code re-write, however a solution that seems to work well enough is it simply detect when the widget is destroyed and write the string "\n\nexit()" to the interpreter. This calls the exit function inside the interpreter, which causes the call to shell.interact to finish, which makes the thread finish.
So without further ado, here is the modified code:
import tkinter as tk
import sys
import code
from threading import Thread
import queue
class Console(tk.Frame):
def __init__(self, parent, _locals, exit_callback):
tk.Frame.__init__(self, parent)
self.parent = parent
self.exit_callback = exit_callback
self.destroyed = False
self.real_std_in_out = (sys.stdin, sys.stdout, sys.stderr)
sys.stdout = self
sys.stderr = self
sys.stdin = self
self.stdin_buffer = queue.Queue()
self.createWidgets()
self.consoleThread = Thread(target=lambda: self.run_interactive_console(_locals))
self.consoleThread.start()
def run_interactive_console(self, _locals):
try:
code.interact(local=_locals)
except SystemExit:
if not self.destroyed:
self.after(0, self.exit_callback)
def destroy(self):
self.stdin_buffer.put("\n\nexit()\n")
self.destroyed = True
sys.stdin, sys.stdout, sys.stderr = self.real_std_in_out
super().destroy()
def enter(self, event):
input_line = self.ttyText.get("input_start", "end")
self.ttyText.mark_set("input_start", "end-1c")
self.ttyText.mark_gravity("input_start", "left")
self.stdin_buffer.put(input_line)
def write(self, string):
self.ttyText.insert('end', string)
self.ttyText.mark_set("input_start", "end-1c")
self.ttyText.see('end')
def createWidgets(self):
self.ttyText = tk.Text(self.parent, wrap='word')
self.ttyText.grid(row=0, column=0, sticky=tk.N + tk.S + tk.E + tk.W)
self.ttyText.bind("<Return>", self.enter)
self.ttyText.mark_set("input_start", "end-1c")
self.ttyText.mark_gravity("input_start", "left")
def flush(self):
pass
def readline(self):
line = self.stdin_buffer.get()
return line
if __name__ == '__main__':
root = tk.Tk()
root.config(background="red")
main_window = Console(root, locals(), root.destroy)
main_window.mainloop()
This code has few changes other than those that solve the problems stated in the question.
The advantage of this code over my previous answer is that it works inside a single process, so can be created at any point in the application, giving the programmer more control.
I have also written a more complete version of this which also prevents the user from editing text which shouldn't be editable (e.g. the output of a print statement) and has some basic coloring: https://gist.github.com/olisolomons/e90d53191d162d48ac534bf7c02a50cd
I am trying to code an application that consists of various windows (e.g., generic message dialog, login dialog, main interface, etc.) and am having trouble getting the gtk.main_quit function to be called: either I get a complaint about the call being outside the main loop, or the function doesn't get called at all.
I am a newbie to both Python and GTK+, but my best guess as to how to get this to work is to have a "root" window, which is just a placeholder that is never seen, but controls the application's GTK+ loop. My code, so far, is as follows:
import pygtk
pygtk.require("2.0")
import gtk
class App(gtk.Window):
_exitStatus = 0
# Generic message box
def msg(self, title, text, type = gtk.MESSAGE_INFO, buttons = gtk.BUTTONS_OK):
# Must always have a button
if buttons == gtk.BUTTONS_NONE:
buttons = gtk.BUTTONS_OK
dialog = gtk.MessageDialog(None, 0, type, buttons, title)
dialog.set_title(title)
dialog.set_geometry_hints(min_width = 300)
dialog.set_resizable(False)
dialog.set_deletable(False)
dialog.set_position(gtk.WIN_POS_CENTER)
dialog.set_modal(True)
dialog.format_secondary_text(text)
response = dialog.run()
dialog.destroy()
return response
def nuke(self, widget, data):
gtk.main_quit()
exit(self._exitStatus)
def __init__(self):
super(App, self).__init__()
self.connect('destroy', self.nuke)
try:
raise Exception()
except:
self.msg('OMFG!', 'WTF just happened!?', gtk.MESSAGE_ERROR, gtk.BUTTONS_CLOSE)
self._exitStatus = 1
self.destroy()
if self.msg('OK', 'Everything worked fine') == gtk.RESPONSE_OK:
self.destroy()
# Let's go!
App()
gtk.main()
The nuke function never gets called, despite the explicit calls to destroy.
DIFF On #DonQuestion's advice:
- self.destroy()
+ self.emit('destroy')
- App()
+ app = App()
This didn't solve the problem...
UPDATE Accepted #jku's answer, but also see my own answer for extra information...
First, there is a bit of a test problem with the code: You call Gtk.main_quit() from the App initialization: this happens before main loop is even running so signals probably won't work.
Second, you'll probably get a warning on destroy(): 'destroy' handler only takes two arguments (self plus one) but yours has three...
Also with regards to your comment about control flow: You don't need a Window to get signals as they're a GObject feature. And for your testing needs you could write a App.test_except() function and use glib.idle_add (self.test_except) in the object initialization -- this way test_except() is called when main loop is running.
I think #jku's answer identifies my key error, so I have marked it accepted, but while playing around, I found that the MessageDialog does not need to run within the GTK+ loop. I don't know if this is as designed, but it works! So, I broke my generic message dialog out into its own function and then kept the main app altogether in a class of its own, which respects the main loop as I was expecting:
import pygtk
pygtk.require("2.0")
import gtk
def msg(title, text, type = gtk.MESSAGE_INFO, buttons = gtk.BUTTONS_OK):
# Only allowed OK, Close, Cancel, Yes/No and OK/Cancel buttons
# Otherwise, default to just OK
if buttons not in [gtk.BUTTONS_OK, gtk.BUTTONS_CLOSE, gtk.BUTTONS_CANCEL, gtk.BUTTONS_YES_NO, gtk.BUTTONS_OK_CANCEL]:
buttons = gtk.BUTTONS_OK
dialog = gtk.MessageDialog(None, 0, type, buttons, title)
dialog.set_title(title)
dialog.set_geometry_hints(min_width = 300)
dialog.set_resizable(False)
dialog.set_deletable(False)
dialog.set_position(gtk.WIN_POS_CENTER)
dialog.set_modal(True)
dialog.format_secondary_text(text)
response = dialog.run()
dialog.destroy()
return response
class App:
def __init__(self):
# Build UI
# Connect signals
# Show whatever
def appQuit(self, widget):
gtk.main_quit()
def signalHandler(self, widget, data = None):
# Handle signal
# We can call msg here, when the main loop is running
# Load some resource
# We can call msg here, despite not having invoked the main loop
try:
# Load resource
except:
msg('OMFG!', 'WTF just happened!?', gtk.MESSAGE_ERROR, gtk.BUTTONS_CLOSE)
exit(1)
# n.b., Calls to msg work even without the following code
App()
gtk.main()
exit(0)
I have an interface created with Glade. It contains a DrawingArea and buttons.
I tried to create a Thread to refresh every X time my Canva. After a few seconds, I get error messages like:
"X Window Server 0.0", "Fatal Error IO 11"
Here is my code :
import pygtk
pygtk.require("2.0")
import gtk
import Canvas
import threading as T
import time
import Map
gtk.gdk.threads_init()
class Interface(object):
class ThreadCanvas(T.Thread):
"""Thread to display the map"""
def __init__(self, interface):
T.Thread.__init__(self)
self.interface = interface
self.started = True
self.start()
def run(self):
while self.started:
time.sleep(2)
self.interface.on_canvas_expose_event()
def stop(self):
self.started = False
def __init__(self):
self.interface = gtk.Builder()
self.interface.add_from_file("interface.glade")
#Map
self.map = Map.Map(2,2)
#Canva
self.canvas = Canvas.MyCanvas(self.interface.get_object("canvas"),self.game)
self.interface.connect_signals(self)
#Thread Canvas
self.render = self.ThreadCanvas(self)
def on_btnChange_clicked(self, widget):
#Change map
self.map.change()
def on_interface_destroy(self, widget):
self.render.stop()
self.render.join()
self.render._Thread__stop()
gtk.main_quit()
def on_canvas_expose_event(self):
st = time.time()
self.canvas.update(self.map)
et = time.time()
print "Canvas refresh in : %f times" %(et-st)
def main(self):
gtk.main()
How can i fix these errors ?
To use Python threads in PyGTK, you need to surround any access to shared GTK objects with gtk.gdk.threads_enter() and gtk.gdk.threads_leave(). See also the threads_enter() method.
You might even be better off using GTKs functions for periodic function calls, such as timeout_add(...) and timeout_add_seconds(...) (note that recently these functions moved around a bit, and in your installation they might be in GObject and not GLib).
Some other notes:
Subclassing Thread objects is the Java way of doing things, not the Python way. The Python way is to define a function or callable object that what you need and pass it to a Thread constructor.
You should not be using _Thread__stop(). It is name mangled for a reason, which is that it forms part of the internal mechanism of the Thread object and is not for normal public use. Instead, you should use one of the thread-safe objects (eg. a Condition object) and check it from the function you passed to your Thread object in step one. Alternatively, set your Thread as a daemon, so it will automatically die when the program exits.
The usual extension for GTKBuilder files is ".ui", not ".glade" (even though Glade itself appends ".glade" as the default extension.)
I hope this helps.
I'm trying to code something that downloads a file from a webserver and saves it, showing the download progress in a QProgressBar.
Now, there are ways to do this in regular Python and it's easy. Problem is that it locks the refresh of the progressBar. Solution is to use PyQT's QNetworkManager class. I can download stuff just fine with it, I just can't get the setup to show the progress on the progressBar. Here´s an example:
class Form(QDialog):
def __init__(self,parent=None):
super(Form,self).__init__(parent)
self.progressBar = QProgressBar()
self.reply = None
layout = QHBoxLayout()
layout.addWidget(self.progressBar)
self.setLayout(layout)
self.manager = QNetworkAccessManager(self)
self.connect(self.manager,SIGNAL("finished(QNetworkReply*)"),self.replyFinished)
self.Down()
def Down(self):
address = QUrl("http://stackoverflow.com") #URL from the remote file.
self.manager.get(QNetworkRequest(address))
def replyFinished(self, reply):
self.connect(reply,SIGNAL("downloadProgress(int,int)"),self.progressBar, SLOT("setValue(int)"))
self.reply = reply
self.progressBar.setMaximum(reply.size())
alltext = self.reply.readAll()
#print alltext
#print alltext
def updateBar(self, read,total):
print "read", read
print "total",total
#self.progressBar.setMinimum(0)
#self.progressBar.setMask(total)
#self.progressBar.setValue(read)
In this case, my method "updateBar" is never called... any ideas?
Well you haven't connected any of the signals to your updateBar() method.
change
def replyFinished(self, reply):
self.connect(reply,SIGNAL("downloadProgress(int,int)"),self.progressBar, SLOT("setValue(int)"))
to
def replyFinished(self, reply):
self.connect(reply,SIGNAL("downloadProgress(int,int)"),self.updateBar)
Note that in Python you don't have to explicitly use the SLOT() syntax; you can just pass the reference to your method or function.
Update:
I just wanted to point out that if you want to use a Progress bar in any situation where your GUI locks up during processing, one solution is to run your processing code in another thread so your GUI receives repaint events. Consider reading about the QThread class, in case you come across another reason for a progress bar that does not have a pre-built solution for you.